Tank washers

ABSTRACT

A device for washing the inside of a tank, vat or other container using cleansing liquid under pressure, the device comprising a base intended to be rotatably mounted, in the use of the device, on a pipe carrying a supply of the cleansing liquid, and also comprising at least one nozzle pivotably mounted on the base in such a way that the or each nozzle is connected to the interior of the pipe, and wherein the or each nozzle is oscillatable in a plane transverse to that in which the base rotates, the or each nozzle being oscillatable by means of a piston and cylinder assembly, and wherein the base is rotatable about the pipe by a one-way drive mechanism secured to the end of said pipe and actuated by the nozzle or nozzles.

United States Patent lnventor Michael Robinson 5 Ref Cited A I No gggff' UNITED STATES PATENTS f m 28 1970 2,680,650 6/1954 Miscovich 239/227 Patemed Dem 7 1 2,757,956 8/1956 Salminen 239/239 X Assignee Streamiisher Limited Primary Examiner-M. Henson Wood, Jr.

St. Peter Port, Guernsey, England Assistant ExaminerEdwin D. Grant Priorities July 29, 1969 AttorneyWaters, Roditi, Schwartz & Nissen Great Britain Feb. 20, 1970 Great Bmain 8301/70 ABSTRACT: A device for washing the inside of a tank, vat or other container using cleansing liquid under pressure. the device comprising a base intended to be rotatably mounted, in

TANK WASHERS the use of the device, on a pipe carrying a supply of the 21 Claims, 7 Drawing Figs. cleansing liquid, and also comprising at least one nozzle pivotably mounted on the base in such a way that the or each US. Cl. 2233990222379, nozzle is connected to the imerior ofthe Pipe. and wherein the in CI Bosh 3/00 or each nozzle is oscillatable in a plane transverse to that in Fieid 239/227 which the base rotates, the or each nozzle being oscillatable by 237 means ofa piston and cylinder assembly, and wherein the base is rotatable about the pipe by a one-way drive mechanism secured to the end of said pipe and actuated by the nozzle or nozzles.

70 Q 22 O 4 40 2a l3 v L A I P 10 12 PATENTEDUEC nan SHEU 2 BF 5 FIG? FICA

PATENTED DEC 7 I971 SHEET 3 OF 5 F IG.3

o Illlliu PATENTED DEC 7 l97l SHEET t [1F 5 PATENTEDDEB nan 3525425 SHEET 5 OF 5 TANK wnsnsns This invention relates to tank washers of the type intended to be mounted on a pipe carrying a supply of cleansing liquid that extends into the tank or vat to be washed, and at least one nozzle that oscillates while spraying the inside of the tank with the liquid.

An object of the invention is to provide a washer that is simple in construction and reliable in operation, and that does not need a train of reduction gears, as is the case with turbinedriven washers.

According to the invention there is provided a device for washing the inside of a tank, vat or other container using cleansing liquid under pressure, the device comprising a base intended to be rotatably mounted, in the use of the device, on a'pipe carrying a supply of the cleansing liquid, and also comprising at least one nozzle pivotably mounted on the base in such a way that the or each nozzle is connected to the interior of the pipe, and wherein the or each nozzle is oscillatable in plane transverse to that in which the base rotates, the or each nozzle being oscillatable by means of a piston and cylinder assembly, and wherein the base is rotatable about the pipe by a one-way drive mechanism secured to the end of said pipe and actuated by the nozzle or nozzles.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be directed, by way of example, to the accompanying drawings, in which:

FIG. I is a side view of a tank washer according to the invention,

FIG. 2 is a sectional plan view along line AA of FIG. 1,

FIG. 3 is a further side view of the device of FIG. I, as seen in direction D of FIG. 1,

FIG. 4 is a sectional plan view along line -8 of FIG. 1 of the one-way drive mechanism,

FIG. 5 is a sectional side view of the washer of FIG. 1,

FIG. 6 is a side view in the opposite direction to that of FIG. 1, and

FIG. 7 is a sectional view along line C-C of FIG. 6.

Referring to FIG. I of the drawings, the tank washer is supported by an internally threaded mounting l, which is screwed onto the lower end of a pipe, which pipe serves both to supply high-pressure liquid to the washer and also to support same inside the tank to be washed. 'Ihe mounting I is formed with a pair of flats 2 in order that a spanner or wrench may be used to secure the mounting l to the pipe. About the lower end of the mounting I there is rotatably supported a base 3, to which the rest of the parts of the washer are secured or connected. As best shown in FIG. 2, the base 3 is substantially hollow, the cavity therein consisting basically of two holes. One of these, a vertical hole 4, accommodates the lower end of the mounting l. The other, a horizontal hole 5, has passing therethrough a hollow shaft 6. It will be seen that both the mounting 1 and the shaft 6 have laterally extending orifices therein in the region of the holes 4 and 5. Thus liquid from the supply pipe may pass through the orifices in the mounting 1, through the hollow base 3, and into the shaft 6. The shaft 6 also has four circular, radial orifices at one of its ends, over which orifices are mounted four radial nozzles 7, 8, 9 and 10. The high-pressure liquid is thus expelled out of said nozzles. The nozzles are provided with longitudinal vanes 11, which are at right-angles to each other. These serve to remove swirl from the jet of liquid.

The positioning of the shafts l and 5 at right angles provides a simple lightweight assembly in which there are no residual hydraulic forces. Therefore the bearings may be of flight construction.

The tank washer operates by rotating or indexing the base 3 about the mounting 1, and simultaneously oscillating the nozzles about the shaft 6 by, preferably, 92. Thus a path is traced across the wall of the tank by a jet of liquid from any particular nozzle. The period of oscillation of the nozzle is not a multiple of the period of the rotation of the base 1, so that the path traced by a jet is not the same as each revolution of the base 3. Thus the whole area of the tank is covered.

As may be seen in FIG. 2, the nozzles are screw-threaded into the shaft 5, and thus may be removed and replaced with plugs. Removal of the nozzles 7 and 8 and their replacement with plugs means that jets of water cover only parts of the tank lower than the tank washer. 'l'hus open top tanks may be cleaned. Removal of the nozzles 8 and 10, together with a reduction in the amplitude of oscillation of the nozzles to aboutl 5 from the horizontal caused by increasing the length of the crank driving the nozzles, means that the jets of water or other liquid cover only a band around the tank, level with the washer. Thus a scum line may be cleaned.

Movement of the nozzles is effected by means of a piston operated by the high pressure liquid from the supply pipe. The piston is shown at 12 in FIG. 5. The piston 12 is secured at one end of a connecting rod 13 by nuts 35, which are kept from working loose by the compound know under the Trade Mark Loctite," and reciprocates in a cylinder 14. The cylinder 14 is secured to the base 3 by means of a support pillar 25 and pipes i5 and I6.

The piston 12 is driven by a supply system best shown in FIG. 7. Said supply system consists of the two pipes 15 and 16, the pipe 15 opening into the upper end of the cylinder 14, and the pipe 16 opening into the lower end of the cylinder 14. The upper ends of the pipes 15 and 16 are supported in a block 17. The block 17 has bored therein three holes 18 in the outer ones of which support the pipes 15 and 16, while the inner one is lined and has reciprocating therein a piston valve 19. As can be seen in FIG. 7, the holes 18 are connected by bores, such that water or other liquid from an inlet 20 is directed into one or other of the holes 18, depending on the position of the piston valve 19. Simultaneously, the other bore is open to the atmosphere so that liquid may be exhausted therethrough. The stroke of the piston valve I9 is limited by means of bushes 2i.

The piston valve 19 is moved at the ends of the stroke of the piston 12. At or near the center of the shaft on which the piston valve 19 is mounted there is a bearing 22. Rotatably mounted in the bearing 22 is a stud 29 located at one end of a valve control member 23. The valve control member 23 consists of two parallel bars which are connected at their ends and at the center by studs similar to the stud 29. At the other end of the member 23 is a roller 24 which bears against the support pillar 25. On the end of the connecting rod 13 remote from the piston I2 there is secured an element 26 through which passes a toggle 27. The toggle 27 is widened at each end and has a further widened portion near its upper end, so that the element 26 moves in the narrow portion of the toggle 27 and abuts against the widened portions, the member 23 being linked to the upper end of the toggle 27.

The toggle 27 is of such a length that just before the ends of the strokes of the piston 12 the element 26' abuts against one or other of the widened portions of said toggle 27 and pushes the toggle either up or down, so pushing or pulling the end of the member 23. The member 23 has attached at the end thereof near the bearing 22 two tension springs 28, the other ends of which are secured to a shaft 44 rotatably mounted on the support pillar 25. Thus the toggle 27 is continually urged towards the pillar 25. It will be seen from the drawings that, if the roller 24 is prevented from moving, this will produce a vertical force on the bearing 22. The roller 24 is prevented from moving when in one position by the central part of the member 23 abutting against the lowermost part of the mounting 1, and in the other position by the toggle 2'7 resting on the top of the cylinder 14.

When the piston 12 moves downwardly from the position shown in FIG. 5, towards the end of the stroke the element 26 will abut against the widened end of the toggle 27, which will in turn pull down the end of the member 23 nearest the roller 24. When the member 23 reaches a position just over the horizontal the springs 28 will be fully extended and will thereafter urge the roller 24 downwardly until the bottom of the toggle 27 abuts the top of the cylinder 14. The bearing 22 will thus be moved upwards, in turn moving the piston valve I9 upwards, therefore operating the valve. The piston 12 will now be driven upwards by liquid flowing through the pipe 16, while the liquid above the cylinder will be exhausted through the pipe 15 and thus into the tank.

As the valve control member 23 is not pivoted at any fixed point, the valve 19 is kept hard over in an extreme position until it is tripped by means of the toggle 27. This arrangement ensures that no dead point occurs in which the valve could be stuck in a central position and thus block both outlets to the pipes 15 and 16. The only point at which such a sticking could occur is when the valve control member 23 is in a horizontal position as seen in FIG. and in order to substantially eliminate any such sticking the support pillar 25 is bifurcated at the point where the tension springs 28 are pivoted, and the shaft 44 on which the springs are secured is used to mount a ball race 45 which serves to reduce the friction in a vertical sense between the roller and the pillar 25 to extremely small proportions, so that reliable operation of the valve is ensured.

The means for oscillating the nozzles 7 to is best shown in FIG. 6. This oscillation is provided by the action of the piston 12. There is rotatably secured to the element 26 a connected rod 30. The upper end of the connecting rod 30 is rotatably attached to a crank 31, the other end of which is secured to the end of the shaft 5 remote from the nozzles 7 to 10. It will be clear from the drawings that vertical reciprocation of the piston 12 and thus the element 26 will cause rotational oscillation of the shaft 5 and thus of the nozzles 7 to 10. This oscillation is preferably arranged to be through 92 so that water is sprayed over the entire tank in the plane of the nonles, or through 30 for cleaning specific areas of the tank.

The one-way drive for rotating the washer about the mounting 1 is shown in FIGS. 4 and 5. As can be seen in FIG. 5, to the lower end of the mounting 1 there is attached coaxially with the mounting l a pulley 46, which is prevented from rotating relative to the mounting l by a pin 47. Rotatably embracing the pulley 46 is a sleeve 48. The sleeve 48 is eccentric with respect to the shaft 1 and the pulley 46, to allow the cutting of a groove through one side thereof. A pin 49 extends across the groove, and acts as a pivot for a lever 50 which has a groove therein which engages with the pin 49. A resilient O- ring 51 embraces the pulley 46. It will be obvious from FIG. 4 that the lever 50 will be able to rotate to some extent about the pin 49. It will be seen that, if the lever 50 is pushed in the direction B in FIG. 4, it will engage the pin 49 and a land 52 on the sleeve. Thus the sleeve will rotate about the pulley 46. The sleeve 48 is also formed with a land 53 corresponding to the bottom of the groove in the sleeve, but is at a different level relative to the diameter of the sleeve going through pin 49, than the land 52. Thus, when the lever 50 is rotated in the direction A of FIG. 4, the lever will not impinge upon the land 53 and will be trapped between the pin 49 and the pulley 46. This effect, together with the effect of friction with the O-ring 51, means that the lever is fast with the shaft 1 during attempted rotation in direction A, but is easily rotatable in direction B.

The lever 50 extends outwardly of the machine and in between the nozzles 9 and 10. Thus the lever will be reciprocated as the nozzles move through 90. As the lever is moved in the direction B, the sleeve 48 is rotated about the mounting 1 and the lever 50 merely moves relative to the machine. But when the lever 50 is urged in the direction A of FIG. 4, it bites into the pulley 46, and thus the movement of the nozzles against the lever 50 causes the whole machine to rotate about the mounting 1. Thus the machine is caused to index about the mounting l in irregular steps, which is desirable as then, over several revolutions of the tank washer, the entire surface of the tank to be cleaned is washed.

In order to adjust the length of the indexing stroke performed by the lever, a grub screw 54 is screwed through a diametrical hole in the end of lever 50 so that the end of the screw abuts on the land 52. Screwing the screw 54 will cause the lever to be in engagement with the pulley at all times. The lost motion between the positions of the lever on the land and engaged in the pulley is reduced to a minimum. The indexing movements will thus be large, and similarly the movement will be at a minimum if the screw 54 is withdrawn into the lever 50. The grub screw 54 also serves as a convenient means for taking up wear in the device. It is prevented from working loose, as are most other nuts in the machine, by the material known under the Trade Mark Loctite."

The above adjusting means has the disadvantage that the 0" ring may swell during service and jam the device. A means of overcoming this in machines where no adjustment of the index stroke is necessary is to replace the grub screw with a spring, and to suppress the 0 ring. This has the effect of taking up the backlash in the device and causing the lever 50 to bite into the pulley immediately after it has finished the return stroke. This device is, however, not adjustable.

If the tank washer is to be used in a tank whose length is appreciably greater than its breadth, and/or whose entrance port is at one end of the tank so that the washer has to be mounted near one end of such a tank, it is desirable that, when the nozzles are pointing towards the further end of the tank, they should perform smaller indexing movements than at the nearer end of the tank. This is because if the surface being sprayed is distant, the same angular increment of the nozzles will produce a much larger movement of the jet across the surface of the tank than over a nearer surface. This variation of the angular amount of indexing of the nozzles may be simply and reliably achieved by offsetting the outside edge of the pulley 46 with respect to the shaft 1. It will be seen that the sleeve 48 will thus rotate eccentrically about the shaft 1, so that the pin 49 will move repeatedly towards and away from the shaft 1, the direction at any moment depending on its angular position at the same moment. The slack between the lever 50 and the pulley 46 is thus varied over a 360 revolution and the washer will speed up and slow down progressively through its traverse. The amount of offset is preferably about 0.0l0 inch (0.254 mm. The lever 50 is prevented from moving too far in direction A by a stop 29 depending from the base 3, and abuts on the pillar 25 when moving in direction B. It is desirable to place a mark, such as a paint spot or notch, on the mounting 1 to indicate the direction in which the washer will either index fastest or slowest. The washer may then be easily aligned.

Control of the speed of the washer is effected by a long small bore tube 41 which is placed inside the liquid delivery pipe 16. The tube 41 is held inside the tube 16 by means of a screw-threaded cap 42 In order to allow liquid to pass out of the lower end of the tube 41, an orifice 43 is provided at the lower end thereof. Speed control in tank washing devices of this type is normally effected by a small orifice acting as a throttle. The small bore tube 41 is of a substantially larger bore than the orifice, and is thus not so liable to blockage. The same speed reduction is obtained, however, because of the friction occurring in the length of the tube. Different speeds may be obtained by substituting longer or shorter tubes for the tube 41 by removing the cap 42. Tubes of different length or bore are used for different liquid pressure ranges.

The use of a piston to operate the washer is more simple and robust than the turbines previously used, such turbines requiring a large chain of reduction gears. With the piston shown, at low operating pressures of, for example, 40 lbs. per square inch, about 50 lbs. force of thrust is available.

Seals are provided by polytetrafluoroethylene "0" rings retained in place by a 10 percent squeeze on the O-rings. One ofthe seals is shown at 39 (FIG. 5).

The tank washer that has been described is made mainly of stainless steel, or a similar metal that is resistant to corrosion, particularly to corrosion by the cleaning liquids used therein. The tank washer is simple, robust and reliable in operation and, due to the oscillation rather than rotation of the nozzles, the washer is versatile enough to deal with open top tanks or to be set to clean only particular areas of a tank.

The washer has been described with reference to the position shown in the drawings, i.e., with the longitudinal axis of the washer vertical and with the mounting l at the top. The

words upwardly" and downwardly" and similar terms are to be interpreted throughout this specification as referring to this position but it will be realized that the washer could be used at any angle.

We claim:

1. A device for washing the inside of a container using cleansing liquid under pressure, the device comprising a base (3) intended to be rotatably mounted, in the use of the device, on a pipe carrying a supply of the cleansing liquid, and also comprising nozzle means (8, 9, 10, 11) pivotably mounted on the base (3) in such a way that said nozzle means is connected to the interior of the pipe, and wherein said nozzle means is oscillatable in a plane transverse to that in which the base rotates, said nozzle means being oscillatable by means of a piston (12) and cylinder (14) assembly, and wherein the base is rotatable about the pipe by a one-way drive mechanism secured to the end of said pipe and actuated by the noule means.

2. A device as claimed in claim ll, wherein the base is rotatably about a mounting which is rigidly secured, in the use of the device, to the pipe carrying the supply of cleansing liquid.

3. A device as claimed in claim 2, wherein the base is formed from a substantially cuboid metal block, said block being shaped to define two holes mutually at right angles and communicating with one another, the mounting being rotatably joumaled in one hole and a shaft carrying the nozzle means being rotatably joumaled in the other.

4. A device as claimed in claim 1, wherein the nozzle means is oscillated by a crank mounted on the end of a shaft on which the nozzle means is mounted, the crank being oscillated by a connecting rod of the piston and cylinder assembly.

5. A device as claimed in claim 4, wherein four nozzles are secured to the shaft and extend radially therefrom at intervals of substantially 90.

6. A device as claimed in claim 5, wherein at least one nozzle may be replaced by a plug.

7. A device as claimed in claim 1, wherein the cylinder is supported below said base by at least two pipes and the piston is reciprocable in this cylinder, the pipes carrying cleansing liquid to the cylinder to actuate the piston.

8. A device as claimed in claim 7, wherein the pipes are connected at their upper ends to a valve secured to said base, connected to the supply of liquid and actuated by movement of the piston, the valve switching the flow of liquid from pipe to pipe in order to reverse the direction of movement of the piston at the ends of its stroke.

9. A device as claimed in claim 8, wherein the valve consists of a valve block shaped to define three parallel holes therein, two of the holes containing the top ends of said pipes, the other hole fonning a cylinder for a valve piston, and wherein the holes are interconnected in such a way that a supply of cleansing liquid entering the cylinder flows to one or other of the pipes, depending on the position of the valve piston.

A a device as claimed in claim 9, wherein the valve piston is thrown by means of a toggle passing through an element attached to the ends of a connecting rod of the piston and cylinder assembly, the toggle being widened at each end so that the toggle is moved only near the ends of the stroke of the piston.

11. A device as claimed in claim 10, wherein the toggle pulls or pushes a member attached at one end to said valve piston and having its other end slidably resting on another part of the device, the member having springs extending from said part of the device to a point on the member sliding of the last-mentioned end of the member being limited by stops in such a way that the member is substantially stable in only two positions.

12. A device according to claim 11, wherein the sliding end of said member engages a support pillar that extends between the base and said piston and cylinder assembly.

13. A device as claimed in claim 12, wherein a ball bearing is provided at the point on the support pillar to which the springs are attached in order substantially to eliminate any dead point occurring when the member is normal to the pillar.

14. A device as claimed in clarm l, wherern the one-way drive mechanism comprises a pulley rigidly secured to lower end of said pipe, a sleeve rotatably surrounding said pulley, the sleeve having a tangential groove cut in one side thereof, and a pin mounted across the groove to act as a pivot for a lever lying in the groove, means being provided so that the lever will bite into the pulley if urged in one direction, and will rotate about the pulley if urged in the other, the lever extending between two nozzles and being reciprocated thereby during the use of the device.

15. A device as claimed in claim 14, wherein the groove is deeper at one side of the pulley than at the other so that, if the lever is urged in the direction of the deeper side, the lever will bite into the pulley whereas if the lever is urged in the opposite direction, the lever will abut on the bottom of the groove and the device will rotate about the pulley.

16. A device as claimed in claim 14, wherein the outside circumference of the sleeve is eccentric to the pulley, in order to facilitate the formation of the groove.

17. A device as claimed in claim 14, wherein a resilient 0" ring embraces the pulley in order to increase the friction between the pulley and the lever.

18. A device as claimed in claim 15, wherein a screwthreaded member extends diametrically through the end of the lever, the operative end of the screw-threaded member abutting against the shallow side of the groove.

19. A device as claimed in claim 15, wherein a compression spring is secured diametrically in the ends of the lever, the free end abutting against the shallow side of the groove.

20. A device as claimed in claim 14, wherein the outer circumference of the pulley is eccentric to the axis of the pulley.

21. A device as claimed in claim 1, wherein cleansing liquid is transferred to the piston and cylinder assembly by at least one relatively long straight pipe, the pipe having removably secured therein a coaxial small bore tube through which the cleansing liquid passes in the use of the device, the bore and length of said tube regulating the speed of operation of the device. 

1. A device for washing the inside of a container using cleansing liquid under pressure, the device comprising a base (3) intended to be rotatably mounted, in the use of the device, on a pipe carrying a supply of the cleansing liquid, and also comprising nozzle means (8, 9, 10, 11) pivotably mounted on the base (3) in such a way that said nozzle means is connected to the interior of the pipe, and wherein said nozzle means is oscillatable in a plane transverse to that in which the base rotates, said nozzle means being oscillatable by means of a piston (12) and cylinder (14) assembly, and wherein the base is rotatable about the pipe by a one-way drive mechanism secured to the end of said pipe and actuated by the nozzle means.
 2. A device as claimed in claim 1, wherein the base is rotatably about a mounting which is rigidly secured, in the use of the device, to the pipe carrying the supply of cleansing liquid.
 3. A device as claimed in claim 2, wherein the base is formed from a substantially cuboid metal block, said block being shaped to define two Holes mutually at right angles and communicating with one another, the mounting being rotatably journaled in one hole and a shaft carrying the nozzle means being rotatably journaled in the other.
 4. A device as claimed in claim 1, wherein the nozzle means is oscillated by a crank mounted on the end of a shaft on which the nozzle means is mounted, the crank being oscillated by a connecting rod of the piston and cylinder assembly.
 5. A device as claimed in claim 4, wherein four nozzles are secured to the shaft and extend radially therefrom at intervals of substantially 90*.
 6. A device as claimed in claim 5, wherein at least one nozzle may be replaced by a plug.
 7. A device as claimed in claim 1, wherein the cylinder is supported below said base by at least two pipes and the piston is reciprocable in this cylinder, the pipes carrying cleansing liquid to the cylinder to actuate the piston.
 8. A device as claimed in claim 7, wherein the pipes are connected at their upper ends to a valve secured to said base, connected to the supply of liquid and actuated by movement of the piston, the valve switching the flow of liquid from pipe to pipe in order to reverse the direction of movement of the piston at the ends of its stroke.
 9. A device as claimed in claim 8, wherein the valve consists of a valve block shaped to define three parallel holes therein, two of the holes containing the top ends of said pipes, the other hole forming a cylinder for a valve piston, and wherein the holes are interconnected in such a way that a supply of cleansing liquid entering the cylinder flows to one or other of the pipes, depending on the position of the valve piston.
 10. A device as claimed in claim 9, wherein the valve piston is thrown by means of a toggle passing through an element attached to the ends of a connecting rod of the piston and cylinder assembly, the toggle being widened at each end so that the toggle is moved only near the ends of the stroke of the piston.
 11. A device as claimed in claim 10, wherein the toggle pulls or pushes a member attached at one end to said valve piston and having its other end slidably resting on another part of the device, the member having springs extending from said part of the device to a point on the member, sliding of the last-mentioned end of the member being limited by stops in such a way that the member is substantially stable in only two positions.
 12. A device according to claim 11, wherein the sliding end of said member engages a support pillar that extends between the base and said piston and cylinder assembly.
 13. A device as claimed in claim 12, wherein a ball bearing is provided at the point on the support pillar to which the springs are attached in order substantially to eliminate any dead point occurring when the member is normal to the pillar.
 14. A device as claimed in claim 1, wherein the one-way drive mechanism comprises a pulley rigidly secured to lower end of said pipe, a sleeve rotatably surrounding said pulley, the sleeve having a tangential groove cut in one side thereof, and a pin mounted across the groove to act as a pivot for a lever lying in the groove, means being provided so that the lever will bite into the pulley if urged in one direction, and will rotate about the pulley if urged in the other, the lever extending between two nozzles and being reciprocated thereby during the use of the device.
 15. A device as claimed in claim 14, wherein the groove is deeper at one side of the pulley than at the other so that, if the lever is urged in the direction of the deeper side, the lever will bite into the pulley whereas if the lever is urged in the opposite direction, the lever will abut on the bottom of the groove and the device will rotate about the pulley.
 16. A device as claimed in claim 14, wherein the outside circumference of the sleeve is eccentric to the pulley, in order to facilitate the formation of the groove.
 17. A device as claimed in claim 14, wherein a resilient ''''O'''' ring embraces the pulley in order to increase the friction between the pulley and the lever.
 18. A device as claimed in claim 15, wherein a screw-threaded member extends diametrically through the end of the lever, the operative end of the screw-threaded member abutting against the shallow side of the groove.
 19. A device as claimed in claim 15, wherein a compression spring is secured diametrically in the ends of the lever, the free end abutting against the shallow side of the groove.
 20. A device as claimed in claim 14, wherein the outer circumference of the pulley is eccentric to the axis of the pulley.
 21. A device as claimed in claim 1, wherein cleansing liquid is transferred to the piston and cylinder assembly by at least one relatively long straight pipe, the pipe having removably secured therein a coaxial small bore tube through which the cleansing liquid passes in the use of the device, the bore and length of said tube regulating the speed of operation of the device. 